UK light-heavyweight Buatsi earned a win yet underwhelming debut to life under fresh promotional backing with a decision win over Zach Parker in the Manchester arena.
The Olympic medal winner's activity level appeared to earn him a judges' verdict in a close ten-round fight at the boxing arena.
But Parker landed significant shots, connecting with powerful clean blows in a fight where the techniques failed to mesh, with excessive holding marring the action.
The scoring judges judged it 96-94 for to Buatsi, with the third a 95-95.
"It wasn't my best performance but what defines champions? They win," the victor said in the ringside as he was faced disapproval from the spectators.
The British fighter bounced back after his maiden career setback - an epic battle with his previous opponent in February - to earn a twentieth professional win.
Several boxing experts felt Parker, thirty-one, deserved the victory but the Derbyshire fighter suffered the second setback of his 28-bout professional journey.
Buatsi Earns Triumph in Slow Affair
The fighter's advancement has slowed in recent years through management issues and considerable time of lack of fights.
Once tipped as the next star of UK boxing, he now finds himself trying to fulfil that early promise - maybe in what appears to be a ultimate opportunity - under fresh management.
He started carefully, with neither fighter ready to take risks in a calculated initial rounds.
The challenger, whose single earlier setback came at the lower weight class against John Ryder in 2022 after breaking his hand during the bout, was making just his second bout at the higher weight class.
By the fight's midpoint, the underdog had kept it close, creating difficulties for the favorite, who utilized a tight guard to barely take the better periods.
The spectators' acceptance decreased during regular grabbing, with the challenger falling to the floor several times during clinches.
Parker closed well, but several stanzas were challenging to assess. Although, ex-champion the boxing analyst - providing analysis for Dazn - had it strongly leaning for the challenger, awarding Buatsi just only one stanza.
The victor progresses, but with the presence of heavy hitter Benavidez, and Eastern European fighter Dmitry Bivol leading the category, the road to world glory - judging by this showing - still looks steep.
Hatton Memorial Motivates Manchester Derby Fight
In the secondary fight, Arthur beat Rea by divided decision in a terrific all-Manchester contest to secure the European light-heavyweight title.
The arena fell silent for a extremely emotional tribute prior to the bout as ten bells sounded in remembrance of Manchester's own Hatton, who succumbed at age 46 in recently.
It was the initial significant broadcast match card in the city since Hatton's death. As the concluding sound disappeared, the quiet transitioned to a roar of "only one Ricky Hatton".
The fighting within the ring equaled the feeling. The eventual winner was sent to the canvas by a significant blow directly to the face in the second round, rising shakily to his position on the referee's count.
But the red-colored shorts of Arthur soon pressed ahead again. On the opposite side, Rea - in competitive blue - was damaged quickly, noticeable damage appearing under his eye as the pair landed hard punches.
The challenger, 27, delivered effective strikes but the champion, thirty-four, matched the intensity with stinging uppercuts as the intensity rarely dropped over twelve rounds.
Arthur edged the result with official scores of 114-114, narrow lead and wider gap, but both fighters were determined and courageous, all the qualities their inspiration Hatton represented.
